Re: [RESEND PATCH v2 0/5] t: replace incorrect test_must_fail usage (part 6)

> The overall scope of these patches is to replace inappropriate uses of
> test_must_fail. IOW, we should only allow test_must_fail to run on `git`
> and `test-tool`. Ultimately, we will conclude by making test_must_fail
> error out on non-git commands. An advance view of the final series can
> be found here[1].
>
> This is the sixth and final(!) part. It cleans up instances of
> `test_must_fail` that were introduced since the effort began. In
> addition, it finally flips the switch and makes test_must_fail only
> allow a whitelist of commands.
>
> This series is based on the merge of 'master' and
> 'dl/test-must-fail-fixes-5'. In addition, this series was tested by
> merging with 'seen~1' (to ignore the reftable failures) to ensure no
> in-flight topics will require more changes.
>
> The first part can be found here[2]. The second part can be found
> here[3]. The third part can be found here[4]. The fourth part can be
> found here[5]. The fifth part can be found here[6].
>
> Changes since v1:
>
> * Add a code comment to force_color()
>
> * Do not allow nested env's in test_must_fail_acceptable()
>
> * Clean up the env-processing case code
>
> * Give an example on how to use `!`.